Researchers at the University of Florida have identified 17 bacterial species living under mushroom caps that collectively drive bacterial blotch disease, a persistent infection affecting white button mushrooms for more than 100 years.
The team published their findings in Microbiological Research, revealing that this polymicrobial infection involves far more complexity than previously understood. Bacterial blotch causes dark, unsightly lesions on mushroom surfaces, rendering crops unmarketable despite being safe to eat. The disease has resisted control efforts for decades, partly because researchers underestimated the number of bacterial species involved.
The discovery that at least 17 different bacterial species participate in the infection reshapes how scientists approach treatment. Rather than targeting a single pathogen, disease management now requires strategies addressing multiple bacteria working together. These organisms colonize the space directly beneath mushroom caps, creating an ideal microenvironment for infection to establish and spread.
White button mushrooms rank among the most widely cultivated fungi globally, contributing significantly to food production and nutrition. The disease inflicts substantial economic losses on growers, who must discard infected batches. Understanding the bacterial consortium behind blotch disease opens pathways to develop more effective interventions, whether through selective breeding for resistance, targeted antimicrobial approaches, or cultivation practice modifications.
The polymicrobial nature of the infection explains why single-agent treatments have failed. Future research will likely focus on identifying which bacterial species play leading versus supporting roles in disease development, and whether certain combinations prove more virulent than others. This knowledge could enable researchers to disrupt the infection network more effectively.